| 摘要 |
The compounds of formula (I) wherein R1 and R2 are, independently, hydrogen, straight or branched chain alkyl or mono- or bi-cyclic alkyl; A is an N-heterocycle which may be substituted by alkyl, perfluoroalkyl, alkoxy, perfluoroalkoxy, amino, alkylamino, dialkylamino, alkylsulfonamido, alkylcarboxamido, nitro, cyano or carboxyl; or, A is a substituted phenyl group containing one or two substituents selected from cyano, nitro, alkyl, perfluoroalkyl, alkoxy, perfluoroalkoxy, amino, alkylamino, dialkylamino, sulfamyl, alkylsulfonamido, arylcarboxamido, alkylsulfonyl, perfluoroalkylsulfonyl, arylsulfonyl, chloro, bromo, fluoro, iodo, 1-imidazolyl or carboxyl; or a pharmaceutically acceptable salt thereof, are smooth muscle relaxants. |
